In recent weeks they've putting DensGlass (the yellow panels) on the exterior, which will soon start being covered in exterior siding panels I imagine. A lot of work is happening on the roof for HVAC, I think. Exterior work behind Luigi's seems to be behind the backstage sides, and maybe that's due to whatever (fingers crossed) treatment they do to make that work (it's park guest visible). It seems the truss closest to Mission Breakout stalled.
Overall, I think the building shell will be done this summer, perhaps excluding the facade screens and any behind-Luigi's theming. That gives them a year to install the sets (likely trucked in from local scenic shops) and install, calibrate, test ride, projections, show effects. It's not easy for them to hit Fall '28 but I would feel confident enough to bet on it.